Circuit breaker



H. P. DNLE.

CIRCUIT BREAKER.

APPLICATION FILED ocT. 2s, 1921.

Patented '0015. 10, 1922.'A

/NVE/V T08 A TTOHNE Patented ct. 10', 1922.

UNITED STATES PATENT OFFICE.

HAROLD OTTER DONLE, F MERIDEN, CONNECTICUT, ASSIGNOR T0 THE CON- NECTICUT TELEPHONE ELECTRIC COMPANY, INCORPORATED, OF MERI- DEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

. cmcurr naman Application tiled October 2B, 1921,. lSerial No. 511,075.

' To all whom it may concern:

- a modification.

Be it known that I, HAROLD P. DONLE, a citizen of the United States of America, residing at Meriden, Connecticut, have invented a new and useful Improvement in Circuit Breakers, of which the following is a specification. y My invention relates to circuit breakers, and consists in providing means whereby said device will be automatically operated.

in the event an excessl amount of current is passed through the circuit controlledby said breaker. i

The object of my invention is to provide an exceedingly simple, compact, eilicient, and reliable construction.

In the accompanying drawings- Figure 1 is a longitudinal section of the circuit breaker as it would appear when installed.

Fig. 2 is a cross section on the of Flg. 1.

Fig. 3 is a longitudinal sectional view of line 2 2 Fig. 4 is a cross section on the line 4-4 of Fig. 3. y

I will first describe that particular form of my invention which is shown in Figs. 1 and 2, in which, 1 represents an insulating base of circular'outline., 2 is a spring of conducting material which is mounted at one end on the base V1 at one sidevof the center. 11a are.y side pieces preferably integral with the ba'se 1 and forming a channel between them. The spring 2 is bowed so as'to extend across the channel toward the opposite side of the base. 3 is what I will term a thermostatic trigger, which is also made of conducting material and is ordinarily constructed of two layers of metal-which have different co-eicients of expansion, whereby changes in temperature will cause said trigger to bend.v One end of this trigger is secured to the base 1,while the vother end is Vprovided with alatch nose 4. Suitable terminal pieces orconnections on the base 1 may be provided for the fixed end of the sprin y is aplunger whic `is mounted in a suitable guide bushing 6. 7 is a plate secured tg the ends of the side members The bushing 6 has a threaded connection with the plate 7. 8 is a light spring coiled around 2 and the trigger 3. '7 5` that part of the plunger, 5 which projects through the bushing. 5a is a head on the outer end of the plunger. The sprin 8 operates in a direction to cause the hea 5 to be seated against the outer end of the bushmg 6. 9- represents a portion of a supporting panel such as the dashboard of an automobile.

wherein the free end of the spring 2 is electrically disconnected from the trigger 3 and operates to push the plunger 5 outwardly so that itV will operate as a tell-tale to indicate that the circuit breaker is open. To close the circuit, the operator presses in on the plunger 5. This movement causes the spring .2 to snap under the nose 4' of the tr1gger 3 so that the arts will assume approximately the position shown in solid lines of Fig. 1.

In the event a short circuit occurs in the circuit controlled by this breaker, the excess current passing through the thermostatic trigger will heat up said trigger and cause it to bow backwardly so as to release the spring 2 and break said circuit. -The use of such a device will be found to be of great convenience in automobile use as a substitute for a fuse. It not infrequently happens that automobile owners fail to provide themselves with extra fuses and thus frequently find themselves helplessly stalled, or with lights out. By this equipment, as soon as the short circuit ordefect is corrected, the operator may reset the automatic breaker by merely pushing in on the pluner 6. g In the form lshown in'Figs. 3 and 4 I have provided the. base with aA threaded plug extension 10 of the type usually employed on an incandescent lamp, the construction of which is clearly shown in Fig.

3, and is too well known to require special I have provided the base with a supple'- .mental housing or casing 11, which maybe 4 The `device is held toV such a vpanel by being clamped between the 10o description. In this form of the invention, l

in Figs. 3 and 4, one of said blades being of a material such as a brass or copper alloy, which has a ne current carrying capacity, the other blade being made of steel which has a fine spring quality which will f not easily become set but wliicli is much more reliable with brass or the like for the purpose of functioning as a spring. So also the trigger indicated at 3 may be similarly laminated. By this construction, the durability and dependability of the device may be substantially*increased.

1. An automatic circuit breaker comprising a base of insulating material, a thermostatic trigger mounted on said base, a latch shoulder adjacent the free end of said trigger, a bowed spring secured at one end to said base, the other end lying ad]acent to said latch shoulder and arranged to be engaged therewith and disengaged there from, a manually operable plunger arranged to engage an inclined portion of said spring to force the latter into engagement with said shoulder by. longitudinal movement of said plunger, a sec-ond spring co-acting with said plunger to move the latter toward said first mentioned spring, the strength of the first mentioned spring being in excess of the strength of the second mentioned spring whereby said plunger will be moved to a tell-tale position when the circuit between the first mentioned spring and the trigger is broken.

2. An automatic circuit breaker comprising a circular base of insulating material, a thermostatic trigger mounted on said base at one side of the axis thereof, a latch shoul-v der adjacent the free end of said trigger, a bowed spring secured at one end of said base and extending across the axis thereof to a point adjacent to said latch shoulder and arranged to be engaged therewith and disengaged therefrom, a manually operable plunger. arranged to reciprocate axially with relation to said base and to engage a portion of said spring to force the `latter into engagement with said shoulder, andl means for yieldingly moving said plunger toward said spring, a bushing 'for said plunger, said spring operating to push said plunger outwardly when the former is disengaged from said trigger.

3. An automatic circuit breaker comprising a circular insulating base having oppo- 4said spring lying adjacent to the free end of said trigger, a late carried by said extensions, said plate aving a central passage, a anged bushing arranged to fit said passage, a plunger carried by said bushing for operating said spring, and a threaded engagement between said plate and bushing whereby said device may be clamped to a dashboard support, or the like.

' 4. An automatic circuit breaker comprising a base of circular outline formed of insulating material, a plate carried by said base, a thermostatic trigger mounted on said base back of said plate, a bowed spring also mounted on said base back of said pla-te, one end of said trigger and one end ot' 'cuit conditions, a plunger acting against an inclined portion of said spring toinove the same into interlocking engagement with said trig er, a bushing passing through said plate an carrying said plunger, the outer end of said bushing having a flanged head, the shank of said bushing being threaded into said plate whereby a support for .said circuit breaker may be clamped between said plate and anged head.

5. An automatic circuit breaker comprising an insulating base, a thermostatically controlled trigger carried thereby, a bowed spring also carried by the base, means for interengaging'one end of said spring with said trigger comprising a manually operable element arranged to engage said spring to forceit into engagement with said shoulder when said element is moved in one direction, a second spring co-acting with said element to move the latter in the aforesaid direction, the strength' of the bowed spring being in excess of the strength of the second mentioned spring whereby said element will be moved to atell-tale position when said bowed spring and trigger are disengaged.

6. An automatic circuit breaker comprising a base, a thermostatically-controlled current-carrying trigger carried thereby and insulated therefrom, a current-carrying spring arranged to be engaged by and disengaged from said trigger, a combined spring-operating and tell-tale device manually movable 

